Method and apparatus to reprofile input speed during speed during speed phase during constrained conditions for a hybrid powertrain system

Abstract

A method to control a powertrain including a transmission, an engine, and an electric machine includes monitoring an input speed, monitoring an output speed, upon initiation of a transmission shift, determining a plurality of input acceleration profiles for controlling the engine and electric machine during the shift, identifying an input acceleration constraint affecting one of the input acceleration profiles, reprofiling the input acceleration profiles based upon the identified input acceleration constraint, and controlling operation of the engine and electric machine based upon the reprofiled input acceleration profiles.

1. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member of said transmission, said method comprising:
 monitoring an input speed of an input member of said transmission; 
 monitoring an output speed of said output member; 
 upon initiation of a transmission shift, determining a plurality of input acceleration profiles for controlling said engine and electric machine during said shift, comprising:
 determining a target input speed synchronizing said input member based upon a destination gear state; and 
 determining said input acceleration profiles based upon transitioning said input speed from an initial input speed to said target input speed; 
 
 identifying an input acceleration constraint affecting one of said input acceleration profiles; 
 reprofiling said input acceleration profiles based upon said identified input acceleration constraint, comprising:
 determining a new target input speed based upon said input acceleration constraint; and 
 reprofiling said input acceleration profiles based upon said new target input speed; and 
 
 controlling operation of said engine and electric machine based upon said reprofiled input acceleration profiles. 
 
     
     
       2. The method of  claim 1 , wherein said powertrain further comprises a second electric machine;
 wherein determining a plurality of input acceleration profiles includes controlling said second electric machine; and 
 further comprising controlling operation of said second machine based upon said reprofiled input acceleration profiles. 
 
     
     
       3. The method of  claim 1 , further comprising:
 determining a slip speed based upon said input speed and said output speed; 
 wherein reprofiling said input acceleration profiles, when said shift includes an inertia speed phase, utilizes said slip speed to approach a zero slip speed. 
 
     
     
       4. The method of  claim 1 , wherein reprofiling said input acceleration profiles further comprises changing a duration of said input acceleration profiles. 
     
     
       5. The method of  claim 1 , wherein said input acceleration profiles are divided into three phases comprising:
 a first phase, wherein an input acceleration is profiled to change said input speed from an initial input speed; 
 a third phase, wherein said input acceleration is profiled to attenuate said input speed to a target input speed; and 
 a second phase bridging said first phase and said second phase; 
 wherein reprofiling said input acceleration profiles is based upon which phase of said input acceleration profiles are affected by said input acceleration constraint. 
 
     
     
       6. The method of  claim 5 , wherein reprofiling said input acceleration profiles comprises changing a duration of said second phase. 
     
     
       7. The method of  claim 1 , wherein determining said plurality of input acceleration profiles and said reprofiling said input acceleration profiles are performed in a clutch slip speed domain. 
     
     
       8. Apparatus for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member, said apparatus comprising:
 an oncoming clutch including an input member and an output member; and 
 a powertrain control system, including programming to monitor an input speed of said input member,
 monitor an output speed of said output member, 
 upon initiation of a transmission shift, determine a plurality of input acceleration profiles for controlling said engine and electric machine during said shift, comprising programming to:
 determine a target input speed synchronizing said input member based upon a destination gear state; and 
 determine said input acceleration profiles based upon transitioning said input speed from an initial input speed to said target input speed; 
 
 monitor an input acceleration constraint affecting one of said input acceleration profiles, 
 reprofile said input acceleration profiles based upon said identified input acceleration constraint, comprising programming to:
 determine a new target input speed based upon said input acceleration constraint; and 
 reprofile said input acceleration profiles based upon said new target input speed; and 
 
 control operation of said engine and electric machine based upon said reprofiled input acceleration profiles. 
 
 
     
     
       9. The apparatus of  claim 8 , wherein said powertrain control system further includes programming to
 determine a plurality of input acceleration profiles for controlling a second electric machine during said shift, and 
 control operation of said second electric machine. 
 
     
     
       10. The apparatus of  claim 8 , wherein programming to reprofile said input acceleration profiles comprises programming to change a duration of said input acceleration profiles. 
     
     
       11. The apparatus of  claim 8 ,
 wherein said input acceleration profiles are divided into three phases comprising
 a first phase, wherein an input acceleration is profiled to change said input speed from an initial input speed, 
 a third phase, wherein said input acceleration is profiled to attenuate said input speed to a target input speed, and 
 a second phase bridging said first phase and said second phase; 
 
 wherein said programming to reprofile said input acceleration profiles is based upon which phase of said input acceleration profiles are affected by said input acceleration constraint. 
 
     
     
       12. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member of said transmission, said method comprising:
 monitoring an input speed of an input member of said transmission; 
 monitoring an output speed of said output member; 
 determining a slip speed based upon said input speed and said output speed; 
 upon initiation of a transmission shift, determining a plurality of input acceleration profiles for controlling said engine and electric machine during said shift, wherein said input acceleration profiles are divided into three phases comprising:
 a first phase, wherein an input acceleration is profiled to change said input speed from an initial input speed; 
 a third phase, wherein said input acceleration is profiled to attenuate said input speed to a target input speed; and 
 a second phase bridging said first phase and said second phase; 
 
 identifying an input acceleration constraint affecting one of said input acceleration profiles; 
 reprofiling said input acceleration profiles based upon said identified input acceleration constraint, said reprofiling comprising:
 determining a recalculated target input speed based upon said output speed and a destination gear ratio; and 
 reprofiling said input acceleration profiles in order to attenuate said input speed to said recalculated target speed based upon which phase of said input acceleration profiles are affected by said input acceleration constraint, said reprofiling comprising changing a duration of said second phase; and 
 
 controlling operation of said engine and electric machine based upon said reprofiled input acceleration profiles; 
 wherein said changing a duration of said second phase comprises, when only said first phase is affected by said input acceleration constraint, changing said duration of said second phase to equal a slip speed differential that must be accomplished through said second phase divided by a rate of change of slip speed that will occur through said second phase. 
 
     
     
       13. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member of said transmission, said method comprising:
 monitoring an input speed of an input member of said transmission; 
 monitoring an output speed of said output member; 
 determining a slip speed based upon said input speed and said output speed; 
 upon initiation of a transmission shift, determining a plurality of input acceleration profiles for controlling said engine and electric machine during said shift, wherein said input acceleration profiles are divided into three phases comprising:
 a first phase, wherein an input acceleration is profiled to change said input speed from an initial input speed; 
 a third phase, wherein said input acceleration is profiled to attenuate said input speed to a target input speed; and 
 a second phase bridging said first phase and said second phase; 
 
 identifying an input acceleration constraint affecting one of said input acceleration profiles; 
 reprofiling said input acceleration profiles based upon said identified input acceleration constraint, said reprofiling comprising:
 determining a recalculated target input speed based upon said output speed and a destination gear ratio; and 
 reprofiling said input acceleration profiles in order to attenuate said input speed to said recalculated target speed based upon which phase of said input acceleration profiles are affected by said input acceleration constraint, said reprofiling comprising changing a duration of said second phase; and 
 
 controlling operation of said engine and electric machine based upon said reprofiled input acceleration profiles; 
 wherein said changing a duration of said second phase comprises, when said second phase is affected by said input acceleration constraint but said third phase is not affected by said input acceleration constraint, changing said duration of said second phase to equal a slip speed differential that must be accomplished through said second phase divided by a rate of change of slip speed that will occur through said second phase, additionally adding a portion of duration of said second phase already spent.